Assuming an organized event environment, like a fly-in, or something similar, but NOT formation. Lot's of planes coming and going at all times. You aren't talking to other planes to keep separation. There is no NOTAM for aircraft not participating in the event. The event is at a towered airport. Tower is controlling once you are in immediate vicinity - but they have no radar capability. This question is specific to the period of time you are NOT in the pattern, only before and after entering or departing the pattern. Let's only consider aircraft within 500 feet of your altitude. What type of lateral separation would you consider safe / unsafe?